JPH0748218A - Method for controlling plant blight - Google Patents

Abstract

PURPOSE:To provide a method for controlling blight of cultivated vegetables, etc., caused by microorganisms. CONSTITUTION:Plant blight can be controlled by treating a plant with an aqueous micelle solution or an aqueous dispersion of a mixture of lysophospholipid and an unsaturated fatty acid and/or medium-chain fatty acid or a mixture of lysophospholipid, an unsaturated fatty acid and/or medium-chain fatty acid and oil and fat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling diseases caused on plants such as agricultural crops, horticultural plants and plants.

[0002]

2. Description of the Related Art A variety of pests and diseases are caused in plants and other trees that are artificially cultivated such as crops, and many pesticides are used to control many of these harmful effects. Control of plant diseases (prevention and treatment) that started in Bordeaux liquid in olden times
Most of the pesticides used as chemicals, that is, fungicides, are chemical synthetic products, have cytotoxicity and / or metabolic toxicity, and in fact, many are harmful to plants and humans other than pathogenic bacteria. Is. Recently, there is a tendency to avoid the use of chemically synthesized pesticides due to the spread of organic farming methods, pesticide-free cultivation, and pesticide-less cultivation. However, it is extremely difficult for organic farming and pesticide-free cultivation to escape from the occurrence of diseases. Especially in greenhouse cultivation, which tends to be hot and humid, pesticide-free cultivation is difficult, and organic cultivation requires great effort. For this reason, wood vinegar, which is a natural product and highly safe for living organisms, has been attracting attention, and its use in agriculture for soil disinfection, fertilizer production for addition to manure / compost, promotion of plant growth, pest repelling, etc. is increasing. (Japanese public Sho 63-24964, Yamabayashi magazine, 19
1978, p. 28, Lumber Journal, 35, 564, and 1021).

The present inventors have previously shown that (1) a mixture of wood vinegar and lysophospholipids, and (2) a mixture of wood vinegar, lysophospholipids and fatty acids have a synergistic effect on plant activation and pest repellent. He discovered that and filed a patent for this composition. Although these compositions were found to have a controlling effect on plant diseases, they were extremely insufficient for (1) and effective for (2), but the presence of a wood vinegar was It did not seem to be essential for disease.

[0004]

[Problems to be Solved by the Invention] An effective, nontoxic and safe disease control agent against organic diseases, greenhouse gardening / cultivation, home gardening, fruit trees, garden trees and lawns, etc. against diseases caused by fungi The need for is extremely large. Nevertheless, the means have been extremely limited, such as breeding of plants highly resistant to the disease, use of grafted seedlings, and improvement of cultivation methods. The present invention aims to control plant diseases, especially fungal diseases, by using safe natural products.

[0005]

Means and Actions for Solving the Problems The present inventors have
For the purpose of non-toxic and safe control of plant diseases, micellar or aqueous dispersion of a mixture of lysophospholipid and unsaturated fatty acid and / or medium chain fatty acid in water is applied to the plant by a method such as spraying. It was discovered that it is possible to effectively control plant diseases, especially diseases caused by fungi, and completed this discovery. That is, it is a method for controlling plant diseases, which comprises applying an aqueous dispersion of a mixture of lysophospholipids and fatty acids to plants.

First, the composition ratio of the mixture of lysophospholipid and fatty acid which is the basis of the present invention is characterized in that the molar ratio of fatty acid / lysophospholipid is 0.5-2. Although the lysophospholipid used here does not need to be specified as animal properties such as egg yolk and plant properties such as soybean, it is derived from plant seeds such as soybean lysophospholipid, and is the weight of lysophospholipid in the total phospholipids. A ratio of 50% or more is suitable. Next, the unsaturated fatty acid having 16 or more carbon atoms used in the present invention is one kind selected from the group consisting of linoleic acid, linolenic acid, other unsaturated fatty acids, and medium chain fatty acids having 8 to 14 carbon atoms. A mixture of various fatty acids such as soybean oil fatty acid and coconut oil fatty acid can be used.

In the second aspect of the present invention, the phospholipid is treated with phospholipase A-2 and then used without separating and removing all or part of the fatty acid from the mixture after the reaction. In this case, if necessary, another fatty acid can be added separately. This mixture gives transparent or almost transparent aqueous micelles or dispersions in the range where the enzymatic reaction proceeds sufficiently, the lysophospholipid content is high, and the molar ratio of fatty acids does not exceed 1.

The third aspect of the present invention is to treat the pasty phospholipids containing fats and oils (general soybean phospholipids used for foods) with phospholipase A-2, and then to remove all or part of the fatty acids and fats and oils. It is used without separation and removal. In this case, the mixture does not become a transparent micelle solution when heated and stirred in addition to water, but becomes an aqueous dispersion containing a fine oil and fat emulsion, which is also suitable as a method for controlling plant diseases of the present invention.

The lysophospholipid used in the present invention is soybean,
Phospholipids and egg yolk phospholipids derived from plant seeds such as rapeseed and corn were deacylated with phospholipase A,
As a monoacyl phospholipid, phospholipase A-2 derived from the pancreas is usually used, and phospholipase A (A-1 and A-2) derived from a microorganism can also be used. An oil-containing paste-like crude phospholipid that is by-produced as a gum during the purification of soybean oil or rapeseed oil, particularly soybean lysophospholipid made from crude oil-containing crude soybean phospholipid, is inexpensive and suitable as a raw material of the present invention.

Decomposition products of phospholipid phospholipase A (A-1 and A-2) are phospholipids which have not reacted with monoacylglycerophospholipids such as lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylinositol and lysophosphatidic acid. Contains lipids and fatty acids. Lysophospholipid purified from these mixtures by treatment with acetone or ethyl acetate is suitable as a raw material of the present invention. Chemically synthesized lysophospholipids can be used as well.

It is difficult to convert all phospholipids into lysophospholipids by the above enzyme treatment, and diacyl phospholipids remain, but the amount of lysophospholipids is 50% of the total phospholipids.
It is suitable for the raw material of the present invention that the content is at least wt%. Further, for the purpose of the present invention, it is more preferable that the content of lysophospholipid in the total phospholipid is high, but 80% by weight
The effect is not so different as above. If such a lysophospholipid is used, for example, an ordinary crude soybean phospholipid is treated with phospholipase A-2, then water is removed, and treated with a solvent such as acetone or ethyl acetate to obtain an oil component and a fatty acid. It can be the one without. In each case, the amount of lysophospholipid is calculated as its absolute amount.

The unsaturated fatty acids having 16 or more carbon atoms used in the present invention include linoleic acid, linolenic acid, oleic acid,
It is a fatty acid such as arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, or a mixture thereof, and a small amount of a saturated fatty acid such as palmitic acid or stearic acid may be mixed. In this respect, the fatty acids of vegetable oils such as soybean oil are also suitable. The medium-chain fatty acid used in the present invention is caprylic acid, capric acid, lauric acid, myristic acid, or a mixture thereof, and a small amount of another fatty acid may be mixed. Therefore, fatty acids such as coconut oil and palm kernel oil are also suitable.

In the first aspect of the present invention, the lysophospholipid is calculated as a molecular weight of about 500, and the absolute amount of the lysophospholipid is mixed with the fatty acid in a molar ratio (fatty acid / lysophospholipid) of 0.5 to 2. When the fatty acid is a mixture, it is calculated by its average molecular weight. The aqueous micelle solution or the aqueous dispersion of the mixture is heated with a suitable organic solvent such as an equal volume mixture of ethanol / hexane to make them compatible with each other, and then the solvent is distilled off and further dissolved in water by heating. It can be prepared by When the fatty acid has a medium chain and the relative amount to the lysophospholipid is relatively small, the fatty acid can be directly added to the aqueous micellar solution of lysophospholipid under heating and stirred to be dissolved therein. When the above molar ratio is 0.5 or less, the controlling effect against plant diseases is insufficient, and even when it is 1 or more, it is effective, but in the case of unsaturated fatty acid, when the molar ratio becomes 1 or more, in the mixed micelle of lysophospholipid / fatty acid. Uptake of fatty acids into the
In the case of capric acid having 10 carbon atoms, if the molar ratio is 2 or more, fatty acid is likely to be similarly precipitated.

When a plant is subjected to an aqueous micelle solution or aqueous dispersion of the mixture, the concentration thereof is preferably about 0.2 to 0.005% by weight in terms of the total amount of lysophospholipid and fatty acid. (Hereinafter, the concentration of the solution of the present invention is indicated by the total amount of lysophospholipid and fatty acid), but usually as a solution of about 0.1% by weight to 0.01% by weight as a solution of a plant before disease onset or disease onset. It is sprayed on the above-ground part, especially the leaf surface of the plant afterwards by means such as spraying. For solutions in this range
The pH is usually 5-6 weakly acidic. The concentration and spraying frequency of the mixture vary depending on the species of plant (whether grass or tree), seedlings or shoots, post-growth condition to some extent, and disease state.

In the herbaceous dicotyledonous plant, after germination, the true leaves 2-3
It is suitable to spray a thin solution from the time of printing.
Spray once every 0 or 20 days. For vegetables, it is also effective to irrigate the seedbed or ridge soil with a solution of about 0.2% by weight before sowing or planting of seedlings in the warm season. In the case of fruit trees of the family Rosaceae, it is effective to apply it just before the fall of the scales in early spring and then apply it regularly. Even after the onset of the disease, it is possible to prevent the progress of the medical condition and cure the disease if the time is early. In this way, for example, diseases such as vegetables, fruits and garden crops that are particularly susceptible to diseases such as greenhouse cultivation, that is, downy mildew, powdery mildew, rust, gray mold, anthracnose, scab and the like. It has become possible to control many diseases caused by fungi.

A mixture of lysophospholipid and unsaturated fatty acid and / or medium chain fatty acid has an excellent surface-active effect,
The ability to reduce surface tension, which is not found in ordinary highly safe surfactants,
It is known by the present inventors that they have strong penetrability and spreadability on leaves (Japanese Patent Laid-Open No. 2-203928 and Journal of American Oil Chemist Society, Vol. 67, 12). Issue, 1008 pages (1990
Year))). However, it has not been known at all that an aqueous micelle solution or an aqueous dispersion of this mixture has an excellent controlling effect against plant diseases.

Lysophosphatidylcholine has a lytic action against Pseudomonas aeruginosa and Streptococcus (see M. Rahab et al., Inframation, Vol. 3, page 365), and certain lysophospholipids by the present inventors. Was also known to have lytic properties against bacteria of the genus Bacillus (Tsuchita and Fujita, announced by the Japan Fermentation Engineering Society in 1991). However, the aqueous micellar solution of lysophospholipid alone was extremely insufficient in its effect on plant diseases.

Surprisingly, however, it was observed that a mixture of lysophospholipids and fatty acids, which is a partial enzymatic decomposition product of phospholipids constituting biological membranes, has a remarkable control effect against phytopathogenic fungi. Phospholipase A-
2 is an enzyme ubiquitous in cell membranes and organelle membranes, and when this enzyme acts, a lysophospholipid / fatty acid mixture is locally generated there. Therefore, it was originally considered harmless to living organisms.

The reason for the above effect is unknown. But,
M. J. According to Bucovac et al., The invasion of leaves of the aqueous solution into the tissues via the pores has a surface tension of 30 mN.
/ M or less (plant ・
Physiology, 49, 813 (1972), and American Journal of Botany, 61.
Vol., P. 100 (1974)). The surface tension of the aqueous solution of the lysophospholipid / fatty acid mixture of the present invention is not less than the critical micelle concentration, and in the case of an equimolar mixture of soybean lysophospholipid and fatty acid, it is 28-29 mN / m for polyunsaturated fatty acid and medium chain fatty acid. In the case of 25-27 mN / m, the apparent surface tension becomes 25-28 mN / m when a small amount of soybean oil is mixed.
Therefore, it is estimated that the penetration and permeation of the aqueous solution from the leaf surface pores into the leaf tissue is facilitated. This effect appears to be facilitated by the good spreading properties of this solution during foliar application and the increased concentration of the mixture due to water evaporation after application.

According to a recent study conducted by the present inventors, soybean lysophospholipid and a mixture of soybean lysophospholipid and unsaturated fatty acid or medium chain fatty acid have water-soluble protein binding property at room temperature. It is presumed that the above-mentioned actions may cause some abnormalities in the cell membranes and membrane-bound enzyme proteins of relatively weak fungi. Although the lysophospholipid itself does not have a strong penetrating effect, the combination of the lysophospholipid / fatty acid mixture provides a strong penetrating, wetting and spreading effect. However, the effect of the method of the present invention is that an industrial surfactant having the same penetrating, wetting and spreading effects as the lysophospholipid / polyunsaturated fatty acid mixture, such as polyoxyethylene nonylphenol ether, is used instead. It can be seen that it is different from the mere surface-active action in that it cannot be obtained even when used.

In carrying out the present invention, an aqueous micelle solution or an aqueous dispersion of a lysophospholipid / fatty acid mixture or a lysophospholipid / fatty acid / oil / fat mixture is applied to plants, but the method is not specified. But usually the aerial part of the plant,
Spray on leaves, stems, etc. The above aqueous solution or dispersion may be prepared in advance as a concentrated solution and diluted before use, but in this case, ordinary preservative measures for storage are required. Addition of other auxiliary components to the aqueous solution of the mixture of the present invention can be carried out within a range that does not impair the effects of the present invention. In carrying out the present invention, other chemical components such as pesticides may be used in combination, and in that case, a pesticide reducing effect can be expected.

[0022]

EXAMPLES The effects of the present invention will be verified with reference to the preparation method and examples of the mixture of the present invention, but the present invention is not limited thereto. In the following,% means all% by weight,
All parts mean parts by weight.

Materials used in the examples of the present invention will be described below. Preparation of lysophospholipid: As an effective method for preparing lysophospholipid, there is an improved method of the method disclosed in JP-A-64-16595. As an example, 200 g of tap water containing 2 g of pancreatic phospholipase A-2 (Novo Lecitase 10-N) is added to 1 kg of heated oil-containing soybean phospholipid (Ajinomoto Co., Inc.) and stirred to form a W / O emulsion. None, after degassing, the container was filled with nitrogen gas, left standing at 60 ° C. for 40 hours to complete the reaction, and the oil layer separated on the top was removed by centrifugation. Acetone (2 kg) was added to the mixture of the reaction product containing water and the oil that had precipitated, and the mixture was stirred, and the precipitate was centrifuged to recover lysophospholipid as an acetone-insoluble matter. The solvent was distilled off to obtain soybean lysophospholipid. It was As a result of analysis, this product contained 80% lysophospholipid. SL of this soybean lysophospholipid
It is abbreviated as P80.

Preparation of lysophospholipid / fatty acid / oil / fat mixture: In the same manner as in the preceding paragraph, the mixture of the reaction product containing oil and water obtained was 30% lysophospholipid.
And contained 16% of fatty acids mainly of linoleic acid. This mixture is abbreviated as OLF30 / 16. Furthermore, this reaction product was subjected to centrifugation to remove a part of the oil layer (oil and fatty acid) separated on the upper side, and contained 34% of lysophospholipid and 15% of fatty acid. This mixture is OLF34 / 15
Is abbreviated.

[Soybean lysophospholipid, trade name Basis LP]
As a result of analysis of -20E (Nisshin Oil Co., Ltd.), it contained 71% soybean lysophospholipid. This product is abbreviated as SLP71.

Fatty acid: all the fatty acids used are those manufactured by NOF Corporation, Extra Linoleic 90
(90% linoleic acid), Extra linolenic 90
(Linolenic acid 90%), NAA-122 (lauric acid 9
9%), NAA-102 (capric acid 99%, A-12
40 (coconut fatty acid).

Preparation of the Mixture of the Invention 63 parts of SLP80 and Extra Linoleic 90
Of 18: 2 / LP8 was obtained by compatibilizing 28 parts of the above in 500 parts of a mixed solution of ethanol / hexane and distilling off the solvent.
It is abbreviated as 0. This is an equimolar mixture of soybean lysophospholipid and linoleic acid. Similarly, SLP80 63
2 extra linolenics for each division
8 parts, 20 parts of NAA-122, 17 parts of NAA-102
Parts, 21 parts of A-1240 and
These are 18: 3 / LP80 and 12 / LP8, respectively.
It is abbreviated as 0, 10 / LP80, CO / LP80. These are all equimolar mixtures of soybean lysophospholipids and fatty acids.

A mixture of 63 parts of SLP80 and 14 parts of NAA-122, and 63 parts of SLP80, NAA-
A mixture of 122 parts of 122 was prepared in the same manner as described above, and these were prepared as 12 / LP0.7 and 12 / LP1.5, respectively.
Is abbreviated. Extra for 70 parts of SLP71
28 parts of linoleic 90, 20 of NAA-122
Parts were treated as before to give a mixture. Each,
It is abbreviated as 18: 2 / LP71 and 12 / LP71.

For 95 parts of the OLF34 / 15, A
5 parts of -1240 was added, and the mixture was heated to about 70 ° C and mixed well. This mixture is abbreviated as OLF / CO / 52.

Preparation of Aqueous Solution of the Present Invention Each mixture obtained by the above method was heated and dissolved in tap water and applied to plants. The concentration shown in the following examples was soybean lysophospholipid. Calculated with the total value of fatty acids.

Example 1 In Example 1, with respect to strawberries, 18: 2 / LP80, 1
8: 3 / LP80, 18: 2 / LP71, OLF34 /
15 solutions and controls, and SLP80 solutions for comparison, a total of 6 were tested. In the cultivation of strawberries (variety: Onamine) in a greenhouse, 6 sections of 8 m ² were provided in the greenhouse. After fertilization was carried out by the usual method, disease-free seedlings were planted in late September. The fixed planting is a flat ridge with 4 rows and m per division
^A total of 64 disease-free seedlings of ² plants were planted per ² plants.

On the day before planting, each aqueous solution of the present invention, as a comparative example, an aqueous solution of SLP80, was added to each test plot, respectively.
It was irrigated with 21 / m ² as 0.2% (water was used as a control). Insulation started in mid-October (daytime, growing season 30 ° C, then around 25 ° C, nighttime 12-7 ° C), and then mulch and lined curtains were sequentially applied to clean axillary buds and introduce bees. Harvesting started from the end of the month, 4
The cultivation was terminated in the beginning of the month. During this period, the spraying of the lysophospholipid / fatty acid mixture solution of the present invention was started 2 weeks after planting, and a 0.03% solution was sprayed every 10 days so that both sides of the leaves were wet. Initially, it was about 0.21 per 8 m ³ , and after growth was about 1-1.21. Pesticide was not sprayed, and powdery mildew, anthracnose, chlorosis, and wilt that occurred on leaves and fruits during this period were observed, and the number of sporadic strains was recorded. The results are shown in Table 1. In contrast to the severe disease in the control group, the disease condition of the plant body by the application treatment was light, and the control effect of the present invention was recognized.

[0033]

[Table 1]

Example 2 In Example 2, as in Example 1, strawberries (variety:
12 / LP80, 10 / LP80, 12
/LP0.7, 12 / LP1.5, a solution of OLF30 / 16 and a total of 6 types were tested. The results are shown in Table 1, but the disease state of the control group was severe, whereas the disease state of the plant body by the application treatment was light, and the control effect of the present invention was recognized.

Example 3 In Example 3, for cucumber, 18: 2 / LP80,
CO / LP80, OLF30 / 16, OLF / CO / 5
A total of 6 different solutions, 2,12 / LP71 solution and control, were tested. In the house forcible cultivation of cucumber, 6 sections of 2.5 × 4 m = 10 m ² were provided in the house. After salt treatment and steam sterilization, fertilization was performed by the conventional method, and 20 grafted disease-free seedlings were planted at the end of December on a mulch-lined 2 bed (variety: Saitama Progeny Breeding Society, Sharp 1 ). Before carrying out the mulching, each aqueous solution of the present invention was irrigated with 0.2% of 41 / m ² (water was used as a control). After that, tunneling was performed by a conventional method to control the temperature at a high level, and after 20 days, after observing the settlement, the temperature was raised and the temperature was controlled at about 25 ° C during the day and about 12 ° C at night.

The application of the lysophospholipid / fatty acid mixture solution of the present invention was started 20 days after planting, and a 0.03% solution was sprayed every 10 days so that both sides of leaves were wet. Initially about 0.41 per 10 m ³ , 1.2-1.51 after growth
It was about. We harvested from mid-February and stopped cultivation at the end of May. During the cultivation period, irrigation and top fertilization were carried out by the usual method, but the pesticide was not sprayed. The causative strains of downy mildew, gray mold and powdery mildew that occurred during this period were observed and recorded. The results are as shown in Table 2. However, the disease state of the control group was severe, whereas the disease state of the plant body by the application treatment was light, and the effect of the present invention was recognized.

[0037]

[Table 2]

[0038]

EFFECTS OF THE INVENTION The effects of the present invention are biological constituent substances,
A new method for controlling plant diseases using a highly safe partial decomposition product of phospholipids has been developed, and a new aspect has been opened for agricultural chemical-free cultivation of vegetables, horticultural crops and the like.

Claims (9)

[Claims] 1. A method for controlling plant diseases, which comprises applying an aqueous dispersion of a mixture of lysophospholipids and fatty acids to plants. 2. The method according to claim 1, which is an aqueous dispersion of a mixture comprising a lysophospholipid and a fatty acid in a molar ratio of 0.5-2 fatty acid / lysophospholipid. 3. The method according to claim 1, wherein the lysophospholipid is a plant seed-derived lysophospholipid. 4. The method according to claim 3, wherein the lysophospholipid is soybean lysophospholipid. 5. The fatty acid comprises one or more selected from the group consisting of unsaturated fatty acids having 16 or more carbon atoms and saturated fatty acids having 8 to 14 carbon atoms.
The method described. 6. A plant disease characterized in that a mixture of lysophospholipid and fatty acid is a decomposition product of phospholipid derived from plant seeds by phospholipase A-2, and an aqueous dispersion of this mixture is applied to a plant. Control method. 7. The method according to claim 6, wherein the mixture of lysophospholipid and fatty acid is a decomposition product of soybean phospholipid with phospholipase A-2. 8. A method for controlling plant diseases, characterized in that the mixture of lysophospholipids and fatty acids is a mixture further containing vegetable oil, and a dispersion of this mixture in water is applied to the plant body. 9. The method according to claim 8, wherein the mixture of lysophospholipid and fatty acid is a degradation product of crude soybean phospholipid containing oil by phospholipase A-2.